Method of blending or combining fibers and product



United States Patent "ice .METHOD OF. BLENDING 0R COMBINING FIBERS AND PRODUCT Harold Garner, Kingston, Ontario, Canada, Abraham J.

Rosenstein, New Marlboro, Mass, and Nathan Rosenstein, West Hartford, Conn, assignors to Spunize Co. of America, Inc., Unionville, Conn., a corporation of Connecticut N0 Drawing. Filed May 22, 1959, Ser. No.814,953

12 Claims. (Cl. 57-140) This invention relates to crimped natural and synthetic fibers, filaments, spun yarns, continuous filament yarns, tows, slivers and rovings, hereinafter collectively referred to as fibers, wherein highly crimped fibers are blended or combined with fibers having lesser or no crimp.

This invention further relates to improvements intextile yarns of the synthetic linear condensation polymer type Where the fibers can be crimped and where the crimp can be set into the fibers by steam, superheated water or other methods of heat treatment. More particularly, the invention relates to yarns having high bulk and loft and a more wool-like quality than has been heretofore obtainable in yarns manufactured from polyamide, polyester or similar fibers.

This invention further relates to the combining of highly crimped or bulked roving, tow, spun yarn or continuous filament yarn with a roving, tow, spun yarn or continuous filament yarn of conventional bulk or crimp or no crimp, or any combinations thereof, in desired proportions to enable the resultant blend of yarn to become extremely bulky and voluminous when the yarn or subsequent fabric is in its end form.

This application is an improvement over the related copending applications, Serial No. 519,052, filed June. 30, 1955, now abandoned, Serial No. 556,589, filed December 30, 1955, now abandoned, Serial No. 706,485, filed December 31, 1957, now abandoned, and Rosenstein et al., US. Patent Number 2,715,309.

As pointed out in the above cited applications and patent, ordinary synthetic continuous filament tows or yarns as well as regularly crimped tows or yarns have certain latent disadvantages which have limited their use. Also, previous crimps had to be limited in number per inch and amplitude to enable carding. Fabrics made from yarn out of such material; while having some bulk, are limited in use because of the type of single plane crimp or the amplitude and number of crimps per inch. For example, where a conventional spun yarn of a given diameter and yarn count made of conventionally crimped staple is assigned a bulking index of 100, a continuous filament yarn of the same approximate yarn. count, processed according to the patent to Rosenstein et al., No. 2,715,309, results in a diameter approximately three times as great and this affords a bulking index of 1790 or approximately eighteen times the bulk of a conventionally crimped spun yarn.

In the use of such spun yarns or tows for the production of textiles, wearing apparel, sewing thread and industrial products, it will be noted that the individual filaments thereof lack sufiicient cohesive properties, bulkiness, flexibility, loftiness, softness, resilience and air space between them to permit breathing therethrough. Furthermore, in such spun yarns or tows there is a great tendency towards pilling. Such disadvantages of these types of yarns and tows have prevented the fullest use to which the same can be applied.

In staple fiber production, the thermoplastic property of polyamide, polyester and like fibers has been exploited in the manufacture of crimped fibers where the crimp has beenused as an aid to further processing of the fibers. However, yarns spun from such unset crimped fibers are 3,255,580 Patented June 14, 1966 lean and lacking in loft and character because the crimp is substantially straightened out by processing tensions. As the crimp has not been heat-set into the fibers, the unset crimp that remains is temporary and the crimp lost cannot be restored. An advance, was made in textile spun-yarn production when it was discovered that mechanically induced crimp could be heat-set into polyamide and similar fibers. Although this heat-set crimp is straightened out in the processing operations required to produce the spun yarn, the heat-set crimp can and will recover under further treatment such as steaming, scouring and dyeing. This faculty of crimp recovery causes such spun yarns to contract in length, and the yarns will also bulk up. Yarns spun from crimp-set fibers do, therefore, have slightly more loft and bulk than yarns spun from crimped but non-heat-set fibers but are still lacking in the degree of loft and bulk associated with yarns spun I from fine wools.

We are aware that processes have heretofore been suggested for producing a high-bulk yarn from polymers containing more than of acrylonitrile in the polymer molecule. This effect is achieved by mixing stretched and subsequently relaxed acrylic staple fibers with acrylic staple fibers which have been heated and stretched and then held in unrelaxed or tensioned condition. Heating of a composite sliver of the relaxed and unrelaxed acrylic staple fibers results in shrinkage of the tensioned or unrelaxed component which puckers and folds the relaxed component, thereby increasing the bulk and loft of the heat-treated composite yarn.

A co-pending US. application of Messrs. N. and A. I. Rosenstein, Serial No. 706,485, filed December 31, 1957 (the disclosure being incorporated herein by reference), discloses an apparatus and method for crimping synthetic or natural filaments, fibers, yarns, tows, slivers and roving to obtain crimped filaments or fibers wherein the individual fibers orfilaments are crimped at dilferent planes and/or angles relative to the longitudinal axis of the fibers or filaments of the tow or yarn. Also, this contemplates and provides for producing crimps in the fibers or filaments in a random angle or zig-zag pattern arrangement having an angle in the range of about 30 to This invention is particularly applicable to such multiplanar crimps although it is also applicable to uni-planar crimps wherein all the crimps are formed in substantially the same plane.

A still further object of this invention is to combine highly crimped and bulked continuous filament yarn, roving or tow made according to the invention described in co-pending US. application Serial No. 706,485, filed December 31, 1957, with a continuous filament yarn, spun yarn, roving or tow of conventional bulk or crimp in desired' proportions in a manner to cause a linear contraction of the highly crimped portion so as to pucker and fold the other portion to enable the resultant blendto become bulky and voluminous when the yarn or subsequently resultant fabric is relaxed in its end form.

Another object of this invention is the provision of a spun yarn from crimped staple fibers made from synthetic linear condensation polymers which yarn possesses a higher bulk and loft than heretofore produced. A further object is the provision of a spun yarn from crimped, heat-setpolyamide, polyester and similar staple fibers having greater bulk and loft than heretofore produced. Still a fur-ther object is the provision of a process for producing such high-bulk spun yarns. These and other objects of the invention will be apparent from the description that follows.

The objects of this invention are realized by utilizing j the high degree of crimp-recovery that is obtained when polyamides, polyester and similar filaments and fibers and 3 continuous filament yarns are crimped so that the crimps are substantially symmetrical and permanently set angularly to about 180 of the longitudinal axis of the filament, fiber or yarn. Particularly useful and effective methods of crimping and setting such fibers to have the necessary degree of linear retraction or crimp recovery are disclosed in US. Patent No. 2,715,309 to N. and A. J. Rosenstein and in the co-pending application of the same inventors, Serial No. 706,485, led December 31, 1957. Such highly crimped fibers or continuous filament yarns, when blended with fibers, continuous filament yarns or spun yarns having no crimp or a conventional but much smaller angle of crimp results in a yarn having a substantial degree of retraction with a corresponding increase in bulk and loft. More particularly, the high bulk yarns of our invention are prepared by blending continuous filament yarns or staple fibers cut from synthetic filaments which have been crimped to about a 180 crimp angle with continuous filament yarns, spun yarns or staple fibers cut from uncrirnped or conventionally crimped synthetic or natural fibers, the blend being combined into yarn in the conventional manner. The uncrimped or conventionally crimped component of the yarn blend serves to hold the combination yarn in a dimensionally stable condition during further processing operations, following which heat treatment is applied to the combined yarn thus causing the yarn component previously crimped to about a 180 crimp angle to retract due to crimp recovery, thereby resulting in substantial yarn contraction. This yarn contraction is accompanied by an increase in bulk which results from crimp recovery of the 180 angle crimped component and puckering of the other component in the combined yarn. It is accordingly an essential feature of our invention that one component of the yarn product be capable of being crimped and heat-set to about a 180 crimp angle. Certain types of synthetic fibers such as the polyamides, polyesters and the like are particularly adaptable to such treatment.

In general, the blended yarns of this invention are prepared by crimping polyamide, polyester or the like yarns, filaments or fibers to about a 180 crimp angle and heatsetting the crimp, following which they may be used in continuous filament form or may be cut to staple lengths. When out into staple lengths, this component is carded on a carding machine and blended with a carded sliver composed of fibers which have not been crimped or have been crimped and set in the conventional manner.

One example is a second component comprising a polyamide or polyester fiber wherein the crimp is about a 90 angle as compared to the 180 crimp-set angle in the first component. The two component fibers are blended in a gilling or drafting operation during which adjustments are made to insure that the final blended yarn product contains about 60% by weight of 180 crimped fiber and about 40% by weight of uncrimped or conventionally crimped fiber. This product is then made into a single or plied yarn and subjected to steaming and dyeing operations. For example, steaming operations have resulted in a yarn contraction of 21% while the dyeing operation has caused the yarn to contract approximately 25%. In each case yam contraction is accompanied by a significant increase in yarn diameter and greatly increased loft and bulk. The spun yarn product in its unretracted condition prior to steaming, scouring or dyeing is inert to normal temperature and can be knitted, woven or fabricated into any desired end product. Steaming, scouring or dyeing of the fabricated product will also cause these fabrics to retract and bulk. Once yarns or fabrics prepared in accordance with this invention have been bulked, they possess dimensional stability but still retain a high degree of resilience, bulk and elasticity.

In a specific embodiment of the process of this invention, 180 crimped and heat-set staple fiber was prepared from continuous filament polyamide yarn by crimping the filaments on the crimping apparatus described in the Rosenstein US. Patent No. 2,715,309. Sixty ends of 200 denier continuous filament yarns were fed to the machine. Each yarn end contained 68 filaments so that the nominal denier per filament was approximately 3. The crimped filaments were taken from the machine in the form of a tow and this tow was then heat-set in a setting oven using a steam pressure up to 30 pounds per square inch. Subsequently, the crimped and set tow was cut to 3-inch staple lengths.

The crimped and set stapl fiber was then carded on a Whitin roller top card and converted into carded sliver weighing 45 grains per yard. The carded sliver was then given two operations of gilling on a Warner & Swasey pin drafter. were fed to the pin drafter and the draft adjusted to deliver a sliver weighing 60 grains per yard. At the second drafting operation 6 ends of sliver from the first drafting process were fed to the pin drafter, and again the draft gear was adjusted to deliver a sliver weighing 60 grains per yard.

At a third drafting operation, the highly crimped and set slivers were blended or combined with other slivers composed of polyamide staple fibers having a staple length of 2%" which had been crimped in the conventional manner to about a crimp angle and also heat-set. The denier per filament of the conventionally crimped and heat-set fibers was approximately 3 and the fibers had been craded and given two draftings through pin drafters to produce a pin drafted sliver weighing 80 grains per yard.

In the blending drafting operation, 4 slivers of the crimped fiber were fed to the machine together with 2 slivers of the conventionally crimped fiber to give a blend ratio of 60/40. To insure effective blending of the fiber components, the sliver was then given two more pin drafting operations and the final sliver Weighed 60 grains per yard.

This blended silver was then made into roving on a Whitin Roving Frame. The 60 grains per yard sliver was drafted to produce a 1.5 cotton hank roving. Yarns were spun from these rovings on a Whitin Spinning Frame, the yarns produced being 12s cotton counts and 18s cotton counts. The 12s yarn was spun with 6Z turns of twist and the 18s with 7.5Z turns of twist. These yarns were of normal appearance and had the strength and breaking elongation associated with yarns spun from polyamide fibers, i.e., tenacity wasabout 2 grams per denier and elongation at break was about 28%.

The yarns were than subjected to a series of experiments to determine their ability to contract and bulk. The results of these experiments are as follows:

Example I Yarn which had been spun to 12s cotton counts was made into a 3-ply yarn, the yarn being plied with 3.5 turns of S twist. Skeins were prepared from this yarn and some skeins were subjected to steam only and other skeins subjected to scouring and dyeing. The following results were obtained:

Length of yarn in initial ske-ins, meters 50 Length after steaming, meters 39.5 Length after scouring and dyeing, meters 37.5 1 Contraction of steamed yarn, percent 21 Contraction of scoured and dyed yarn, percent 25 In each case the yarn contraction was accompanied by bulking of the yarn together with improvement in the hand.

Example 2 Yarn which had been spun to 18s cotton counts was made into a 2-ply yarn, the yarn being plied with 4.5 turns of S twist. Skeins prepared from this yarn were At the first operation, 6 ends of carded sliver subjected to the same operations as above. The results were as follows:

Example 3 A 2-ply yarn prepared from the yarn spun to 18s cotton count was knitted into fabric on a circular knitting machine and the fabric was then scoured and dyed. Before scouring and dyeing, the knitted blank was 37%" in length and 20" in width. After dyeing, the length was 26%" and the width 19 /2". This length contraction of 29% in the knitted blank was accompanied by a high degree of bulking action and an improvement in loft and hand.

While the foregoing examples illustrate the use of crimped filaments in staple fiber form, the staple fibers may conveniently be crimped and set at any stage in the spinning operation. For example, crimped polyamide staple fibers or tow which have not been heat-set may be reduced to silver and gilled or drafted to lay the fibers parallel in the fiber strand. One or more of such slivers is then fed into the crimping apparatus as described in US. Patent No. 2,715,309 and crimped to a crimp angle of about 180, following which the highly crimped sliver is set by exposure to steam heat in a setting oven at 30 pounds pressure or any other suitable setting action. Following this operation, the highly crimped and set slivers are given one gilling or drafting operation to open and loosen the crimped fibers prior to blending the 180 crimped fibers with slivers composed of conventionally crimped or uncrimped polyamide and other fibers. Alternatively, conventionally crimped polyamide staple fibers or tows may be taken through the usual spinning sequence and made into a slubbing or roving and crimped and set in this form. Blending of the two fiber components is then obtained in a reroving operation where one end of 180 crimped roving is drafted and re-for-med into a roving along with one end of roving made from conventionally crimped or uncrimped fiber, roving Weights being adjusted to a predetermined percentage blend. Blending or combining of the two different staple fiber components may likewise be obtained before carding, in which event the two different staple fiber components are floor blended in the manner well known in the art and fed through a carding machine. The carded sliver is then drafted and spun into yarn on known and readily available textile machinery.

The polyesters from which the staple fibers may be derived include polyethylene terephthalate, polyethylene terephthalate copolyesters prepared using polyethylene glycols such as polyethylene glycols having molecular weights of 150 to about6000, or polyethers such as the dicarboxymethyl acid of polytetramethylene oxide or the esters of poly-tetramethylene oxide, polydioxal-ane, or polyesters using other acids such as isophthalic or ethylene bis-para-oxybenzoic acids. Polyamides suitable for use in the present invention include polyhexamethylene adipamide and polycaproamide as Well as those disclosed in such patents as US. 2,071,251, US. 2,071,253 and US. 2,130,948

Example 4 Equal lengths of:

(a) 2100 denier continuous filament brightraw nylon yarn, uncrimped.

(b) 2100 denier continuous filament bright nylon yarn which had been subjected to crimping at an angle of 180 to its longitudinal axis, and then heat-set in an autoclave at 265 F. for ten minutes, were twisted one and a half turns per inch Z.

The raw and the crimped filaments were then'double twisted, two and one half turns per inch with an S twist. The resultant yarn was then steamed, and after fully relaxed was found to have contracted to a very substantial degree andto have puckered and folded the raw nylon forming it into loops.

. Inches Length of yarn in trial skeins 36 Length of yarn after steaming 32 Example 5 Two yarns in equal lengths were used, as follows:

(a) 1560 denier continuous filament dull crimp nylon yarn, heat-set in an autoclave at 265 F. for ten minutes.

(b) 1560 denier continuous filament dull nylon yarn crimped at an angle of 180 to its longitudinal axis but not heat-set.

(a) and (b) each were twist-ed at one and one-half turns per inch with a Z twist. Equal lengths of (a) and (b) were then twisted together, two and one-half turns per inch with an S twist. After steaming, the

yarn was found to have contracted in accordance with the following results:

Inches Length of yarn in trial skeins 36 length of yarn after steaming 20 Example 6 A 3-ply y-arn was prepared consisting of the following fibers:

Inches Length of yarn in trial skeins 36 Length of yarn after steaming 28 As indicated by the above examples, the contractionof the composite yarn is to at least about 89% of the original length thereof.

From the foregoing description and from the examples it will be appreciated that it is important to heat-set the fibers that have been crimped to an angle of about 180 to the longitudinal axis thereof, since the heat-setting followed by twisting results in a retraction or recovery which is obtained by steaming. Without such heat-setting and retraction or recovery, the effect obtained in accordance with this invention is substantially lost since the only bulking effect then obtained is the bulking effect that is attributable to the fiber disorientation itself.

The spun yarns illustrated above comprised a blend of polyamide fibers which have been crimped so that the crimps are permanently set angularly to about a 180 crimp angle with polyamide fibers which have not been crimped or have been crimped to a lesser crimp angle. Obviously blends in which the first component fiber is'a polyester and the second component fiber is a polyamide or vice versa are contemplated by this invention. Furthermore, the first highly crimped component fiber may be polyamide or polyester and the second uncrimped or less highly crimped fiber may be acrylic or a natural fiber such as wool or cotton. Many other combinations are, of course, also within the scope of this invention.

Where in this specification and in the appended claims we utilize the term fibers it is to be understood that this term is to be interpreted generically and that it covers all natural and synthetic fibers, Staple, filaments, spun yarns, continuous filament yarns, tows, slivers and rovings and equivalents thereof. Where we refer to crimps that are set angularly to about a 180 crimp angle, We include heat-setting at any time during or after crimping at about 180 to the general longitudinal axis of the fiber, Whether the fiber is inside or outside the crimping box. However, if the fiber is outside the crimping box it should not be subjected to appreciable tension prior to heatsetting.

Where in the specification and claims we refer to a crimp angle of about 180 or the like, including any reference to yarns wherein the yarn has an angle of approximately 180 relative to its longitudinal axis, we refer to yarn produced according to the teachings of the aforementioned patent to Rosenstein et al., No. 2,715,309, wherein the yarn or the like is forced by a pair of rolls into a stuifing box which is full of yarn that has been previously inserted, and wherein the yarn is folded over and over upon itself within the crimping box or chamber. In view of the fact that a straight filament is bent back upon its-elf, this filament is turned through an angle of about 180 and this is what is meant by the expression about 180 relative to its longitudinal axis. It will be appreciated, of course, that after the yarn is released from the crimping chamber, part of the crimp ma) be pulled out, depending upon the degree of tension that is applied to the yarn.

While preferred embodiments of our invention have been disclosed, it is to be understood that modifications as to form, use and arrangement of steps may be made without departing from the spirit and scope of the invention as claimed. For example, instead of providing yarns having no crimp or yarns which have been crimped in accordance with a generally zig-zag pattern to an angle much less than 180, it is possible instead to provide yarns which have been artificially curled or distorted by means of air, such as is disclosed in the patents to Griset, Jr., Nos. 2,874,443, 2,874,444 and 2,874,445, or in the patent to Sellers No. 2,874,446. Any other yarn having much lesser bulk than yarn which is crimped at an angle of approximately 180 may be utilized in place of the specific yarns that have been disclosed herein as yarns having a lesser degree of crimp or bulk than said yarn having a crimp angle of approximately 180. Other modifications and substitutions may obviously be made, and equivalents may be substituted for the specific forms as shown and described herein, without departing from the spirit or scope of the invention as defined in the appended claims.

We claim:

1. A process for producing a yarn of high loft and bulk which comprises crimping and heat-setting fibers of a synthetic heat-setting resin, the said crimps being set angularly to about 180 of the longitudinal axis of the fibers, blending said fibers with other fibers from the group comprising uncrimped fibers and fibers which have been crimped to a crimp angle less than 180 twisting said blend into yarn and heat treating said yarn to contract the 180 crimped fibers and cause puckering of the other fibers to reduce the length of the resultant yarn to at least about 89% of the original length thereof.

2. The product produced by the process of claim 1.

3. The process in accordance with claim 1 wherein the synthetic resin is selected from the group consisting of polyesters and polyamides.

4 The process in accordance with claim 1 wherein said 180 crimps are given a multi-planar orientation.

5. The process in accordance with claim 1 wherein said 180 crimped fibers are twisted staple fiber lengths and said crimps are substantially symmetrical, and wherein said other fibers are staple fibers crimped to a crimp angle less than 180.

6. The process in accordance with claim 1 wherein said 180 crimped fibers are twisted staple fiber lengths and said crimps are substantially symmetrical, and wherein said other fibers are staple fiber lengths of a synthetic linear condensation polymer.

7. The process in accordance with claim 1' wherein said 180 crimped fibers are twisted staple fiber lengths and said crimps are substantially symmetrical, and wherein said other fibers are staple fiber lengths of a synthetic linear condensation polymer which have been crimped to a crimp angle less than 180.

8. The process in accordance with claim 1 wherein said 180 crimped fibers are twisted staple fiber lengths of a polyamide, and wherein said other fibers are twisted staple fiber lengths of a polyamide which have been crimped to a crimp angle less than 180 and heat set.

9. The process in accordance with claim 1 wherein said 180 crimped fibers include a crimped continuous filament yarn, and said crimps are multi-planar.

10. The process in accordance with claim 1 wherein said other fibers are uncrimped continuous filament yarn.

11. The process in accordance with claim 1 wherein said other fibers are uncrimped contiuous filament yarn.

12. A method for producing multi-ply yarn having elastic properties comprising the steps of (a) stuffer box crimping a filamentary yarn component,

(b) air bulking at least one additional filamentary yarn component, and

(c) thereafter assembling and plying the filamentary yarn components by intertwisting the same into a composite structure.

References Cited by the Examiner UNITED STATES PATENTS 2,145,346 1/1939 Dreyfus 57-140 2,174,878 10/1939 Hardy 28--72 2,217,113 10/ 1940 Hardy 2872 2,326,174 8/ 1943 Rutishauser 2872 2,623,266 12/1952 Hemmi 2881 2,686,339 8/1954 Holt 28--81 X 2,715,309 8/1955 Rosenstein et al. 2882 X 2,745,240 5/1956 Brant 57140 2,778,187 1/1957 Leath et a1 57-140 2,793,418 5/1957 Pfau 1966 X 2,794,239 6/1957 Crawford et al 2881 2,811,770 11/1957 Young 28-78 2,948,133 8/1960 Schwartz 2872 X 2,968,857 1/1961 Swerdlotf et al 2872 FOREIGN PATENTS 682,263 11/1952 Great Britain.

DONALD W. PARKER, Primary Examiner.

RUSSELL C. MADER, Examiner.

R. R. MACKEY, Assistant Examiner. 

1. A PROCESS FOR PRODUCING A YARN OF HIGH LOFT AND BULK WHICH COMPRISES CRIMPING AND HEAT-SETTING FIBERS OF A SYNTHETIC HEAT-SETTING RESIN, THE SAID CRIMPS BEING SET ANGULARLY TO ABOUT 180* OF THE LONGITUDINAL AXIS OF THE FIBERS, BLENDING SAID FIBERS WITH OTHER FIBERS FROM THE GROUP CONSISTING UNCRIMPED FIBERS AND FIBERS WHICH HAVE BEEN CRIMPED TO A CRIMP ANGLE LESS THAN 180* TWISTING SAID BLEND INTO YARN AND HEAT TREATING SAID YARN TO CONTRACT THE 180* CRIMPED FIBERS TO CAUSE PUCKERING OF THE OTHER FIBERS TO REDUCE THE LENGTH OF THE RESULTANT YARN TO AT LEAST ABOUT 89% OF THE ORIGINAL LENGTH THEREOF.
 12. A METHOD OF PRODUCING MULTI-PLY YARN HAVING ELASTIC PROPERTIES COMPRISING THE STEPS OF (A) STUFFER BOX CRIMPING A FILAMENTARY YARN COMPONENT, (B) AIR BULKING AT LEAST ONE ADDITIONAL FILAMENTARY YARN COMPONENT, AND (C) THEREAFTER ASSEMBLING AND PLYING THE FILAMENTARY YARN COMPONENTS BY INTERTWISTING THE SAME INTO A COMPOSITE STRUCTURE. 